Field of the Invention
The invention relates to a gas-cooled heat exchanger, in particular a direct intercooler for cooling of a fluid which can flow through the heat exchanger with a heat transfer block featuring a plurality of flow channels, with a first collection chamber and a second collection chamber, wherein the collection chambers are fluidically connected with one another via the flow channels and gas can flow on the outside through the heat transfer block.
Description of the Background Art
Intercoolers are used in modern motor vehicles for increased performance in combustion engines. The intercoolers serve to cool the air flow which is supplied to the combustion engine by, for example, a turbo charger or a compressor.
Through continuous improvements of the heat transfer and with the enlargement of the front surface of the intercoolers used, the cooling capacity has been continuously increased in the past. Particularly the exit temperature of the air flow has thereby been greatly reduced, while the existing pressure in the intercooler has been continuously raised.
This development led to the possibility of a condensate forming inside the intercooler under certain operating conditions. This particularly occurs under environmental conditions characterized by a high, relative air humidity. With ambient temperatures below the freezing point, the resulting condensate can freeze in the intercooler which can lead to a decrease in performance or to a complete blocking of the intercooler. This can lead to an unwanted stalling of the combustion engine. It can also lead to permanent damage of the intercooler.
In best available technology, there are devices which could counteract the formation and freezing of condensate in intercoolers.
DE 10 2012 204 431 A1, which corresponds to U.S. 2013/0252538, discloses a radiator blind which features adjustable and non-adjustable screens with which the flow area of an air passage opening can be modified. The modification of the flow area serves to change the air-mass flow through the air passage opening. With the help of such a device, air flow around a heat exchanger can be purposefully reduced.
DE 10 2005 047 840 A1, which is incorporated herein by reference, discloses an air-cooled exhaust gas heat exchanger which features a covering device with adjustable screens. The covering device is designed in such a way that by adjusting the screens, air flow around the exhaust gas heat exchanger can be permitted or prevented.
Further, the current state of technology features a device that is formed by a cover which can be positioned above or in front of the heat exchanger in order to reduce the air flow around the heat exchanger.
WO 2011/102784 A1 discloses a device which provides a damper inside the intercooler that restricts perfusion of the heat exchanger.
Further, the current state of technology features devices that provide a permanent opening, e.g. formed by a bore hole at the heat exchanger, which allows for a continuous flow off of the resulting condensate.
FR 2 922 962 discloses a device which provides a collection chamber for the condensate and a draining device via which the collected condensate can be discharged from the heat exchanger.
The disadvantage of the devices according to the conventional art is particularly that the adjustable screen device or the cover in front of the heat exchanger generally also impact the cooling performance of the coolant cooler or of other heat exchangers. Moreover, adjustable screens require an activation mechanism and an appropriate control, which is cost-intensive and creates a laborious manufacturing process.
The disadvantage of a damper installed in the heat exchanger is particularly that it requires a controlling and an activation device which can activate and deactivate the damper. This is also complex and expensive.
Providing a permanent opening for the continuous discharge of condensate is disadvantageous since then the heat exchanger is always open. When the engine is at a standstill, water can enter through the opening into the heat exchanger, particularly into the intercooler, which can damage the combustion engine.
The disadvantage of having a collection chamber and a draining device for the condensate is particularly the structural integration of the components into the existing parts. This can lead to significant additional cost.